Abstract 4719: Adenosine Stress Myocardial Perfusion Imaging Using 256-Row Dynamic Volume Computed Tomography
Dynamic volume computed tomography (DVCT), with full cardiac coverage in one gantry rotation, has the capability of providing simultaneous myocardial perfusion imaging (MPI) of the entire myocardium. The purpose of this study was to assess the accuracy of DVCT-MPI to provide relative measurements of myocardial perfusion. Six canine models of non-occlusive coronary artery stenosis were prepared using an open chest model. Following a 5 minute adenosine infusion, iodinated contrast (24 ml) was infused and DVCT-MPI was performed at peak contrast enhancement using the following protocol: 128 × 1mm collimation, 120 kV, 50 mAs. Radioactive microspheres were injected at the time of DVCT imaging to document myocardial blood flow (MBF). Images were reconstructed in short axis with 3mm slice thickness using segmented reconstruction and enhanced beam hardening correction. DVCT images were analyzed using 8 sectors at the mid-ventricular level and compared with microsphere MBF. Mean MBFs in the ischemic and remote territories were 1.47±0.44 and 2.92±0.54 ml/g/min; respectively p=0.04. Mean change in attenuation densities (from baseline) for the ischemic and remote territories were 42±12 and 65±7 HU; respectively (p=0.01). MBF and attenuation densities in the ischemic territory expressed as a percentage of the remote territory was 60±13% and 52±12%, respectively (mean difference = 8%, p=NS). A representative microsphere MBF map is shown in Panels A and B with corresponding gross pathology and CT-MPI shown in Figures C and D⇓. MPI using 256-row DVCT is capable of accurately detecting relative differences in myocardial perfusion.